Signal-call for telephone-lines



(M0de1.) 2 Sheets--Sheet 1.

F. R. RICHMOND.

/ SIGNAL CALL FOR TELEPHONE LINES.

No. 254,155. Patented Feb. 28,1882.

N4 FETERS. PhowLimo n ner. Washington. DV 6.

(ModeL) 2 Sheets-Sheet 2.

F. R. RICHMOND.

SIGNALQALL POE TELEPHONE LINES;

H hlll l l l IIIIIIIIIIIII]! l'l l l l l l' l l'l'l l l l Y UNITED STATES PATENT OFFICE.

FRANCIS R. RICHMOND, OF SPRINGFIELD, MASSACHUSETTS.

SIGNAL-CALL FOR TELEPHONE-LINES.

SPECIFICATION forming part of Letters Patent N0. 254,155, dated February 28, 1882. I Application filed August 8, 1881. (Model.) I

To all whom it may concern:

Be it known that I, FRANCIS B. RICHMOND,

of Springfield, in the county of Hampden and State of Massachusetts, have invented a new and useful Improvement in Signal -Oalls for Telephone- Lines, of which the following is a specification and description.

The object of my invention is to call any particular station on any telephone line or circuit Without calling any other station on the same or any other circuit of the same system, and I accomplish this by the means substantially as hereinafter described and illustrated in the accompanying drawings, in .which Figure I is a side view of a station-bell, its magnet, and the striking mechanism with the side of the inclosing-box removed. Fig. II is a plan View of the magnet and striking mechanism with the top of the box removed. Fig. III is a plan view, showing themanner of hanging the bell-striker. Fig. IV is a side view of one modification of the vibrating weight or bar. Fig. V is a plan view, illustrating the central-office switch-board, the telephone lines or circuits, and the stations thereon. Fig. VI is a vertical transverse section through v the calling-cylinder; and Fig.'VI[ is another modification of the vibrating weight or bar by which the striking mechanism is operated. I

In the drawings, G represents a small box, upon which is placed the station-call-bell, as 16, and in which is inolosed the ordinary magnet, as 10, placed in the line, as 17. This magnet is supplied with an ordinary armature, as

9, in front of which is suspended in suitablydelicate bearings a shaft, as 1, upon which is nicely balanced a wheel or bar, as 3. I prefer thelatter, as it is more easily adjusted to vibrate fast or slow, as hereinafter described. A coiled spring, as 7, has one of its ends secured to this shaft 1, and its other outer end is secured in any desired fixed position, as at the screwf, and an arm, as 8, is attached to the armature 9 of the magnet, which extends upward and forward with its free end resting with a light pressure upon the'coiled spring 7 when the armature is not drawn back to the magnet, and, if desired, an adjusting-screw, as 27, may be used to limit the movement of the armatureawayfromthemagnet. Asomewhat thin and elastic spring, as 14, is secured at one end to any convenient point, as at 13, and extends forward to a point nearly above the vibrating shaft 1, and is connected to the crooked part of said shaft by a wire, as 6, and this spring 14 is provided with a shoulder or projection, as 15.

The bell hammer consists of the ordinary wire or shaft, as 11, which should be somewhat elastic, and provided with its ball or weight, and thewire is also provided with a projection or shoulder, as 26, to impinge against or engage with the shoulder or projection 15 on the spring-catch 14. The lower end of the bellhammer may be conveniently pivoted in a small socket made in the metal frame of the magnet, as shown at 11, and extends upward just behind the armature to apoint quite near the bell, as 16, and a stop of any convenient form and structure, as 12, may be secured to the metal frame of the magnet and extend up to any convenient height to hold the bell-hammer from constant actual contact with the bell.

If a bar, as 3, is used on the shaft 1 to cause it to vibrate, said bar may be slotted nearthe ends, with small weights, as 4, adjusted to'any desired point on the slotted part of the bar by screws turned through the slots and into'the weights. It is evident that with any certain power exerted against the coiled spring 7 to cause theshaftl to revolve the reaction of the spring will move the shaft in the opposite direction or cause it to vibrate to and fro in a rotary manner, and this vibrating movement will be more or less rapid, according as the weights 4 are secured more or less remote from the shaft 1. If a vibrating wheel is used instead of the balance-bar, small weights may be secured through similar slots to the rim of the wheel at points more or less remote from the shaft 1.

If the balance or vibrating bar or wheel should be increased or diminished in its weight, the same result would be obtained in the change in the rapidity of its vibrations; butlprefer to use the movable adjusting-weights described, as the change in rapidity of vibrations of the bar or wheel can be made much quicker and more conveniently and more accurately.

The operation of this device is as follows: Any apparatus desired may be connected with themain line, which can be so adjusted as to make and break the circuit at regular intervals and at different rates, giving regular electric impulses,but at any desired rate or rapidity.

A cheap and convenient device is shown in Fig. V, in which 18 denotesa metallic tubular cylinder, hung in suitable bearings, so as to revolve somewhat slowly when actuated by suitable clock-work, and this cylinder has any desired series of elongated holes, as 22, made therein in circumferential lines and at any desired distances apart. In one-the first seriesthe holes are quite short, with corresponding distances between them. In the next series the holes are a little longer, with the distances between thein correspondingly increased, and so on to the last series. Contact-points, as 19, are arranged in line with the series of holes 22, so as to impinge against the cylinder between the holes in each series, the holes breaking the contact as the cylinder revolves. A local line-wire, as 21, is laid at any convenient point on a switch-board, as I, to be connected at will with any of the circuits, as A B O D E, in the system by switches, as a b c (l e, 850., and this local line 21 may also be connected at will with the cylinder at any desired series of holes, 22, by switches, as 1' 2 3 4* 5 a local battery, as B serving to charge the cylinder and the line 21 with an electric current when the proper connections are made.

Suppose the lines A B O D E to represent the different lines or circuits of a telephone system, and the stations on each to be represented by the numerals 1 2 3 4 5 in the lower part of Fig. V. The vibrating bar, as 3, or balance-wheel above described, at station 1 is adjusted, by its weights, as 4, to vibrate at a rate corresponding to the electric impulses given by the series of holes opposite the switch 1 and contact-point at the cylinder. The vibrating bar or wheel at station 2 is adjusted to vibrate at a rate corresponding to the series of holes at the switch 2,and so on through the series. In this way thevibratingbars or wheels at all the stations 1 on all the circuits will vibrate alike, those at all the stations 2 alike, and so on through all the stations. A small tell-tale magnet and armature may be placed in-the local line 21, on the switch-board.

Suppose the central oflice desires to call station 2 on line B. The operator connects lines B and 21 by the switch I), and connects line 21 with the contact-point and cylinder by the switch 2 and as the cylinder revolves a series of electric impulses is sent through line B, corresponding in rapidity and length with the length of holes 22 and distances between them in the cylinder opposite the switch 2 As the vibrating bar at station 2 on line B is the only one on the line which is adjusted to respond to the impulses caused by the series of holes at 2 the action of the armature in being drawn to its magnet and falling forward again upon the coiled spring 7 will cause the shalt 1 and the bar, as 3, attached thereto, to make a series of vibratory or reciprocating rotary movements, which movements will correspond in rapidity with the electric impulses or with the movements of the armature. These vibratory movements of the shaft 1 and its bar 3, though small at first, will quickly increase in extent, until after from four to six vibrations the shaft 1 will rotate snfliciently to draw the springoatch down out of engagement with the bellhammer, and the latter will fall forward a little into such a position that at each movement of the armature back to the magnet the armature will move the bell-hammer back with it, causing the hammer to strike the bell, and this movement of the bell-hammer against the bell will continue as long as the shaft and its bar continue to vibrate and draw down the springcatch out of engagement with the bell-hammer. After the call is made and the vibrations of the shaft and its bar cease, if the bell-hammer is not left up close to the bell, and there held by engagement with the spring-catch, it will be put into that posit-ion by putting on the battery at the central office to use the line and drawing the armature back to the magnet, which is its position when the line is in use, and when the next call is made, when the armature falls forward the bell-hammer will remain stationary and held by the spring-catch until the vibrations of the shaft are sufficient to draw down the catch and disengage it from the bell-hammer. In this operation the springcatch, as 14, exerts no force whatever upon the bell-hammer to operate the latter, its only function being to hold the bell-hammer stationary during the first few vibrations of the shaft and bar, this being necessary to be done at all the stations on the circuit to prevent all the bells from being struck by the first movements of the armatures in making a signal-call.

Inasmuch as the wcightofthearmature upon the actuatin g-sprin g, as 7, when the former falls forward, is the cause of the vibration of the shaft 1 and its bar, it is evident that instead of using the arm 8 on the armature the shaft 1 may be so placed with reference to the armature that the latter itself, in falling away from the magnet, may fall directly against the coiled spring 7 and actuate the shaft in the same manner by an intermittent pressure upon the coiled spring.

If a balance-wheel is used as attached to the shaft 1 instead of a straight balance-bar, as 3, they might be made of different sizes for different stations on a circuit but as a straight bar with adjustable weights is the most practical, and is easily adjusted to vibrate at any desired rate, I prefer to use a straight weighted bar, as hereinbefore mentioned.

The armature at the tell-tale magnet 30 will indicate to the operator when the party at station 2 had shut off his call if he did not hear the answer. After the call is answered the circuit is broken at the switches 2 and b. In this manner it will be seen that any station on any line of a telephone system may be called without the knowledge of any other station in the system.

The cylinder 18 may be caused to revolve by suitable clock-work at any desired rate of speed, and may be arranged to be wound either once in twenty-four hours or at any other desired stated times.

Inasmuch as the shaft 1 might be made to vibrate by any one of a series of pendulums of different lengths, and be connected with the spring-catch 14-, as shown in Fig. VII, and be made to draw down said spring-catch out of engagement with the bell-hammer by its vibrating movement, it is evident that a vibrating bar in either case operates the vibrating shaft to disengage the spring-catch from the bell-hammer, at intervals corresponding to the electric impulses sent through the line-wire to the station.

Of course the vibrations of the bar 3 and shaft 1 are not sufficient at first to pull down the spring-catch l4c out of engagement with the bell-hammer, but they will be after three or four movements of the armature 9, which will give the required scope of vibration of the bar 3 and shaft 1. I

In order that the party at any station may know when the line is in use, I attach a little colored disk, as 31, to the armature 9, inside the box G,with a hole in the box, so that when the armature is allowed to fall away from the magnet the disk will be exposed to view through the hole, and it can be seen that the line is be ing used, or vice versa, as desired.

Inv practice it would be just as well to have thebell-hammer 11 pivoted or hinged to the armature 9,'s o that the latter could have a movement independent of the bell-hammer, and fall forward andaway from the magnet, while the bell-hammer remained stationary and moved forward after the spring-catch was'moved down by the vibration of the shaft 1, and then both I be moved back together toward the magnet.

Having thus described my invention,what I claim as new is- 1. In a signal-call for telephone-lines, the combination, with a'bell-hammer, of a springcatch adapted to engage with and hold said bell-hammer in a stationary position, a vibratin g shaft connected with said spring-catch and regulated in its movements by a vibrating gage with and hold the bell-hammer in a stationary position and connected with said vibrating shaft, whereby the said bell-hammer may be released from engagement with the spring-catch and the alarm-bell struck by the combined movements of the vibrating shaft and the armature of the magnet, substantially as described.

3. In a telephone system, the combination, with the main line, of a series of signal-calls, each provided with a vibrating bar and shaft connected with and operating to disengage a spring-catch from the bell-hammer and actuated by the armature of an electro-magnet located in the main line, and a revolving cylinr der provided with a series of contact-surfaces, each said series being in adjustment with and controlling the synchronous movements of the vibrating bar and shaft of one of said signal-- calls, whereby any one of the signal-calls in said series may be struck from the central offiee, substantially as described.

FRANCIS R. RIOHMOND.

Witnesses:

T. A. OURTIs, E. M. BISSELL. 

